Mechanical ventilation



Nov. 4,1941. I H. 'MATHIS 2,261,852

MECHANICAL VENTILATION Filed June 15, 1939 2 Sheets-Sheet 1 42 [72wen/07".

Nov. 4, 1941. H. MATHIS MECHANICAL VENTILATION Filed June 15, 1959 2Sheets-Sheet 2 Patented Nov. 4, 1941 OFFICE MECHANICAL VENTILATION HenryMathis, Chicago, Ill., assignor, by mcsne assignments. to MechanoventCorporation, La Porte, Ind., a corporation of Indiana Application June15, 1939, Serial No. 279,281

1 Claim.

This invention relates to an apparatus for and process of mechanicalventilation. It has for one object to provide means for controlling thetemperature in an enclosure such as a room in automatic'response tovariations and conditions within the room. Another object is to providea method for regulating air conditions in an enclosed space such as aroom inresponse to variations in the relative humidity within the closedspace.

Other objects will appear from time to time throughout the specificationand the claim.

The invention is illustrated more or less diagrammatically in theaccompanying drawings,

wherein:

Figure 1 is a vertical section through a room, showing one form of theapparatus installed;

Figure 2 is a vertical section on an enlarged scale showing furtherdetails of the apparatus;

Figure 3 is a schematic showing of the wiring for the apparatusdisclosed.

Like parts are designated by like characters throughout thespecification and the drawings.

I is an enclosed space, here shown as a room, in which there is a fioor2 supported on a fioor beam 3 which is at one end supported in an outerwall 6. This wall is pierced by a window 5. One or more partitions 6 anda ceiling E complete the room. The outer wall is pierced as at 8 topermit the entrance of air. A screen- 9 may be positioned in thisopening and a grill formed of members it may be positioned in theopening if desired. A unit ventilator apparatus is positioned in theroom in communication with the opening 8. As shown, the apparatusincludes a fixed housing portion I l and a removable housing portion [2.The fixed housing portion is preferably made as a permanent part of thegeneral assembly although it might, also, be removable and the removableportion l2 is preferably removable although it might be permanentlyfixed in place. Any suitable housing is within the contemplation ofinvention. Where a removable closure suchas that shown is used, alocking means l3 controlled by a handle it! and a link. may beinstalled. The lock l3 engages an abutment IS on some part of thehousing or framework.

At its back or wall side, the housing is pierced as at l'l to provide apath for the entrance of air from the outside through the opening 8. Theopening I! may be closed by a damper l8. leads communicates with asecond or inward damper 20. The two dampers are joined together by apivoted lever system 2| so arranged and proportioned that the twodampers move simultaneously. Either may be fully closed while the otheris fully open or both may be equally or unequally partially open. Bothcannot be simultaneously closed. The space into which the openings l1and I9 lead has a third opening 22,

through which air may move upwardly. A filter 23 of any suitable natureis positioned in this opening so that all air passing through theopening 2| is filtered.

One or more fans 24 may be positioned within the housing. Each fan is soarranged as to draw air into its casing 25 and discharge it through theopening 26. Positioned above the fans is a heating device 21 which maybe a coil or any other suitable heating means. The air passing throughit is finally discharged from the casing through an opening 28 in whicha grill 29 may be positioned if desired.

The casing portion I2 is provided with an opening 38 in which a-grill 3|may be positioned if desired. The members which form the grill may beinclined, as shown, or may have any a other positron. Slats or dampermembers 32 are pivoted as at 33 and arranged to control the passage ofair through the opening 30. They normally hang downwardly by gravity.Air may enter the casing from the room and the'back -draft dampermembers 32 will not interfere with its movement in that direction.-Should an excessive draft of air in the opposite direction occur, thedamper members 32 will be forced in the closing direction so that theypartially or fully close the opening 30 and prevent the passage of airthrough this opening from the casing into the room.

Suitable motor meansfare provided to operate the blower or fan and tooperate the dampers l8 and Zll, and suitable means are provided forcontrolling the operation of these motor means.

- As shown in Figures 1 and 3, a thermostat 34 and a humidistat 35 areused. They will ordinarily be opened in the room or enclosed space to besubject to conditions in the room. They may, as indicated in dottedlines, be mounted in a single housing or upon a single base where theyThe space into which the opening If opening l9 which may, also, beclosed by a to mount a thermostat out-of-doors.

Such a thermostat would; of course, be affected by the temperature ofthe air before the latter reaches the heating means and would beconsidered an air stream thermostat". Similarly, an air streamthermostat" might be mounted in the housing at the positionY of Figure2.

There it would be affected by the temperature of the air stream after itpasses the heating means. Also, for some purposes, it is desirable Sucha thermostat is indicated diagrammatically as at Z and would, of course,be affected by the outdoor temperature.

As indicated in Figure 3, there are included in the system thethermostat 34 and the humidistat 35 and a blower motor 36 and dampermotor or engine 31. These motors are not shown in detail since a. widevariety of motors or engines might be used and the invention is notlimited to any particular power medium, but may employ electric,pneumatic or any other systems, or a combination of two or more.-

As shown in Figure 3, a wire or conductor 38 leads through a switch 39and a. fuse 40 to the thermostat. Thence, a wire 4| leads to the bloweror fan motor 36 from which a wire 42 completes the circuit. 4

The humidistat is connected to the wire or conductor 38 by a wire 43,and a wire 44 leads from the humidistat to the damper motor 31 fromwhich a wire 45 completes the circuit for that motor. The wire 46 isconnected to the wire 43 and to the wire 4|. An auxiliary switch 41 isinserted in thi portion of the circuit and fmake or breaks this circuit,depending upon the position of the dampers operated by the damperoperating motor 31. The damper motor or engine 31 is connected to theauxiliary switch 41 so that movement of the motor or engine 31correspondingly moved the switch. Thus, the motor 36 is controlledindependently of the thermostat 34 by the humidistat 35 inasmuch as whenthe humidistat operates to energize the damper motor. 31 the switch 41is actuated to effect operation of the motor 36 irrespective of theposition of the contacts of the thermostat 34.

Theexact details of the connection between the engine and the switch arenot shown as many different arrangements may be used.

Although I have shown an operative form of my device, it will beunderstood that many changes in the form, shape and arrangement of.

parts might be made without departing from the spirit of my invention;and I wish that my showing be taken, as in a sense, diagrammatic.

The use and operation of this invention are as follows:

The apparatus substantially as shown operates to control ventilation ofa class room or other enclosed space. When the room is empty, one set ofconditions prevails and relatively little ventilation, is needed andfrequently none is needed". When the room is occupied by people,

a different and a varying set of conditions prevails. The presence ofthe people in the room alters the ventilation need and the apparatusdisclosed acts in response to conditions brought about by the presenceof people in the room to accomplish suitable mechanical ventilation.

Presence of people within the room may alter the humidity in the roomand will influence the dry-bulb temperature. The condition of theout-door air from time to time and from day to day will vary as totemperature and humidity and the ventilation requirements within theroom must take into account the condition of the out-door air becausesome of this air will be normally taken into the room while at sometimes no outside airwill be taken in. At some times it is necessary toheat the air in the room and at others, it is not.

With the general conditions and requirements above mentioned in mind. itis possible to see that the following teps occur in the control of themechanical ventilation of the present invention:

1. Heating of the air is stopped or started automatically in response tothe temperature condition of the air'within the room.

2. Mechanical ventilation is stopped or started or continued in responseto the humidity con-.

dition of the air within the room.

3. Either heating or mechanical ventilation may be stopped, started orcontinued by stopping, starting or continuing the motion of the fan tomove. the air. With the heating element active and the fan stationary,obviously less heating occurs than with the fan in motion.

4. The expression ventilatingaif'ds iconsidered inthis discussion to bethe air coming from the outside and the heating air is contion isregulated by the relative humidity within the room. The importance andeconomy of this is evident when it is considered that many rooms thatmust be mechanically ventilated, and, particularly, school rooms, areoccupied only a small percentage of the day- By making the ventilationdepend on the moisture content of the air within the room, needlessventilation is dispensed with and this is an economy, particularly sinceit avoids the needless introduction of heat into cold out-door air whichmight be needlessly drawn into the room while unoccupied. Therefore, inconjunction with the apparatus shown, it is economical and advantageousto adjust the damper which controls the entrance of out-door air bymeans of an apparatus or in response to an apparatus which" is itselfresponsive to the moisture content of air within the room. As the numberof persons within the room increases, the relative humidity within theroom increases because of the moisture which is given off naturally bythe persons in the room. As the humidity increases within the room, needfor ventilation occurs because of the presence of persons and theapparatus operates to supply that need. As the number of people in theroom decreases,

- the need for ventilation isdecreased, the humidtion of the presentinvention depends. The invention insures optimum air conditions in aroom at all times regardless of season, of outside weather conditions orof room occupancy and of windward or leeward or solar exposure locationof the room.

In its operation, the unit ventilator, which is shown herewith, carriesout effective mechanical ventilation, as above described, and inresponse to the variable conditions indicated. In the particular formshown, the unit ventilator comprises means for replenishing the air inthe room by introducing added air from out-doors and,'also, providesmeans for recirculating the air already within the room, and all of theair that passes through the unit ventilator may be heated or not inresponse to'the conditions prevailing in the room at the time, since theheating means may be turned off or on.

The details of the controlling apparatus are not shown because suchapparatuses are known in the art. Thus, thermostatic mechanisms andhumidistatic mechanisms and motors for driving fans or for controllingand moving dampers are all known in the art, and connections betweenhumidistats and thermostats and the motors which they control are knownin the art and are accomplished by pneumatic systems or electric systemsor otherwise. The invention herewith disclosed is not limited to anyparticular details of this sort. It is within the contemplation of theinvention to use any such mechanisms. Preferably, the control devicesare located in the room itself, as shown in Figure 1, where they aredirectly responsive to the air result; that is to say, responsive to theactual condition of the air within the room. Means for controlling theheat imparted to the air by the heating coil or other heating means maybe of any desired type, and

may include additional or auxiliary means for limiting or controlling,within desirable range, the temperature of the air recirculated, or delivered into the room, by use of a thermostat located in the air stream,either in the fresh air intake or in the path of the air discharged bythe fan or blower before or after its passage through its heatingelement; said thermostat operating upon a valve, of either quick-actionor modulating type, which controls steam or other heating mediumsupplied to the heating element. Optional locations of such limitingcontrol thermostats have been suggested in Figure 2, devices X, Y and Z.

The heat requirements of the room itself are not limited to theheatintroduced by the unit ventilatorbut may also be served by supplementaryheat-introducing means such as auxiliary or supplementing radiators, andthe like.

The presence or absence of occupants in a room may not alter thetemperature of the room and, hence, a ventilating system which operatesin response only to temperature variations will not satisfy allconditions of need but occupants of a room will inevitably change itshumidity and to accomplish ideal ventilation conditions, the controlsmust act in response to humidity variations. That is done inthe presentinvention.

I claim:

In combination in a ventilating apparatus for ventilating a room, a unitventilator including air moving means therein, an outlet means thereforto the room, air heating means therein, an air inlet passage betweensaid unit ventilator and the exterior of the building adapted for thetransmission of untreated outside air to the ventilator, an air inletpassage from the ventilator to the room to be treated, damper meansadapted to control said passages, motor means for said damper means, ahumidistat and a thermostat positioned within the room, an actuatingconnection from said thermostat to said air moving means whereby saidthermostat operates to control the air moving means in response totemperature variations within the room, and an actuating connectionbetween said humidistat and said damper motor means adapted to move saiddampers to vary the supply of outside air in relation to the supply ofrecirculated inside air in proportion to the humidity variations withinthe room.

HENRY MATHIS.

